Sue's Facebook Question and Answer Session 17th September 2010

Name: Lucy GardenQuestion: I've missed Sue's Q-A but please save this for next time - I fell for Abelias on holiday this summer, but will they cope with heavy clay soil? Also, which ones have the best scent? "Kaleidoscope" looks amazing but most of the write-ups I've seen don't mention its scent.

Answer: Abelia is a lovely shrub, and I can easily understand how you fell in love with it. ‘Kaleidescope’ is quite a new variety and should have a nice combination of good sized flowers, with a moderate fragrance. For a stronger fragrance you may want to look out for Abelia triflora, but the flowers will be smaller.

Ideally Abelia prefers to grow in a sheltered, sunny position on fertile, well drained soil, but it is tolerant of quite a range of conditions. Broadly speaking, clay soils are quite fertile, but tend to be poorly drained. Drainage can be dramatically improved by the addition of organic matter. Dig in plenty of well rotted garden compost, leaf mould or manure to improve the soil prior to planting. On really heavy clay, you may find it beneficial to add some coarse grit to help open up the soil structure. Make sure that you dig it in really well to mix it properly with your own clay soil. Abelia is best planted in a sheltered south or west facing position. You can continue to improve its root environment each year by providing a mulch of organic matter in spring, making sure that you don’t mound it up around the stem of the plant. The worms will do the rest of the work for you!

Name: Gill HartQuestion: I have a large hibiscus (tree?), maybe 10-12ft tall. I would like to move it to a better part of the garden. Is that possible? If so how and when is the best time to do it?

Answer: Hi Gill, it is possible to move an established shrub although I’d advise you to reduce the size of your Hibiscus first as this will help it to cope with the move. Reducing the leaf mass will reduce the amount of water lost through transpiration. Ideally you should reduce the size of the shrub over a couple of years, by about a third each time. Prune in early spring, just above a set of leaves or above a node.

Once the shrub has been reduced in size, you can move it to its new home. It’s best to do this when the plant is dormant between autumn and late winter (November-February). Prepare the new planting hole before you begin lifting the Hibiscus from its current position. Make sure you water the shrub well the previous day and tie in any stems that you can to avoid damaging them during lifting.

Choose a cool overcast day to prevent the roots from drying out too quickly. Give the main stem a wide berth and aim to lift as big a root ball out as you can manage so as not to disturb the roots. Any large roots that cannot be lifted should be cleanly cut with a knife or saw. Wrap the root ball in a damp hessian sack to hold it together and prevent the smaller roots from drying out. Re-plant the Hibiscus in its new home immediately. Dig plenty of organic matter (well rotted manure or garden compost) into the new planting hole, and insert a sturdy stake to prevent the plant rocking during windy weather. Firm the plant into its new hole and water well every day, especially in dry periods until the plant has re-established. I would also recommend mulching around the plant as well to retain moisture at the roots.
When moving mature plants there are no guarantees that they will survive. Before you undertake this task I recommend that you take cuttings from fresh new growth in the summer, and propagate some new plants just in case! Although they will take some years to reach the size of your large Hibiscus, a small, younger plant will establish in the new position quickly and easily.

Name: David ThompsonQuestion: Hi Sue. I planted a Forest Flame and a Camellia side by side approx 3 years ago. I planted them too close together and now I want to move the Forest Flame to another part of the garden and keep the Camellia in the same location but move it along slighty to where the Forest Flame used to be. When is a good time to do this? Should I use any special feed afterwards? Also when and how should I prune my Photinia? Many Thanks!

Answer: We have had a similar question from Gill this week and although her plant is probably much larger than your 3 year old shrubs, the same principles apply. The main difference is that yours are evergreens which should be moved either in September/October or in March/April. Remember that if you move them in spring then they will have less time to re-establish a root system before summer, so you will need to be particularly vigilant about watering them. Don’t feed the plants when you first move them, but allow them to establish first, before feeding them with a general fertiliser.

With regard to your Photinia, you can prune it in spring if necessary, by cutting back any old, damaged or misplaced stems to a new shoot lower down the stem. Tip pruning the stems all around the plant by 15cm (6in) will also encourage the production of lots of brightly coloured, young growth.

Name: Pauline WilkinsonQuestion: hello Thompson & Morgan ... Yes., please help.. black bamboo.. I've purchased several from you and they all die..Ii have normal bamboo & red bamboo by their side in the garden, living in the same conditions and they flourish... Is there anything I can do to save them ? thank you! :)

Answer: Hi Pauline. Despite the reputation of bamboos being rampant, vigorous growers you will often find that Black bamboos can take quite a while to establish and tend to be slightly fussy as young plants. They dislike dry, poor soils or soils that sit too wet, and enjoy the addition of plenty of rich, organic matter. They also need a fairly sheltered site as the foliage can easily become wind burnt.

I have had similar problems with my own black bamboo that was planted for years in an unsealed terracotta pot, which unfortunately allowed the soil to dry out quite quickly. I replanted it this spring in a plastic pot with fresh compost and it has literally tripled in size!

My best advice to you is to reassess the conditions that your bamboos are growing in and make appropriate changes. Remember that although bamboos are from the same family, you are growing different species, which each have their own requirements. Hope that helps Pauline.

Name: Jackie MasonQuestion: Hi Sue last year wonderful crop of runner beans from my 'wigwam'. This year practically nothing. Any ideas?

Answer: Hi Jackie, I know a few people who have had the same problem this year. Runner beans are a cool-season crop so it’s probably due to the intense heat we experienced during the early summer. If temperatures are too high then the pods may not set. Also if the plant’s roots get too dry during their critical watering period (when buds and fruit appear) this may cause low production of beans. Regular watering and mulching with organic matter (compost, well rotted manure or general soil improver) will help alleviate this problem. Next year it may be worth trying your runner beans in light shade, just in case we get another run of hot weather!

Name: Daniel Stewart MarshallQuestion: Hi, I just got some Zantedeschia Aethiopica (Arum Lily) seeds and the pack says 'plant immediately'. I was going to plant them in the garden but it is autumn! Do I grow them inside and plant out in spring or do they keep?

Answer: Hi Daniel, Arum Lily seeds should ideally be sown as soon as they are ripe and require warmth to germinate (between 21-27ºC is a good temperature). They can take a few months to germinate so sow them in pots now and keep them warm indoors. Hopefully you’ll be potting them on by late winter so they’re ready to be planted out after the risk of frost has passed. By next year they should be big enough to survive a British winter although make sure you mulch them in the autumn for protection.

Name: Alec DaveyQuestion: I planted some potatoes on the first of September. Will I be able to eat at them at Christmas?

Answer: It is normally recommended that 2nd Cropping potatoes are planted outdoors in early August. If they are planted in a protected environment (e.g. in a polytunnel or greenhouse) then planting can be delayed slightly, but must be planted by the end of the first week of September.

The small potatoes should be ready for harvesting approximately 10 to 11 weeks after planting. Tubers can be harvested as required in November, or left in the ground until Christmas. Cut down the foliage as the leaves wither and yellow, or if they show signs of blight, and protect them from frost by covering them with a thick layer of straw.

The only potential problem with leaving them in the ground for this length of time is that this makes them more susceptible to blight and attacks from slugs and wireworm. If you have grown them in patio bags then you can move them into the shed or greenhouse to reduce the risk of damage.

Name: Becky WhiteheadQuestion: I have tried growing pumpkin twice this year even pollinating them myself and still nothin where am i going wrong?

Answer: Hi Becky, I’m sorry to hear your pumpkins have been unsuccessful. Normally insects will happily pollinate pumpkin flowers. It’s a good idea to grow a mixture of other flowers nearby to encourage the insects and to refrain from using pesticides too, which may kill the beneficial insects.
When you’re hand pollinating it’s important to check the pollen on the male flowers is ripe before applying it to the female flowers (the flower with the bump beneath it). The yellow pollen grains should easily come off on your hand when brushed. It’s also worth considering that lack of water can cause stress in the plant which may prevent fruit set and pumpkins don’t like too much shade either. I hope this has been of some help and good luck for next year!

Name: Belinda EstellQuestion: Hi Sue. I bought some T&M Burgundy Shamrock corms early this year. They've been a talking point in my garden. I've had some in pots and some in a bed. They seem to be dying off now, is this natural and should I do anything or can I leave them where they are? Do they spring back to life next year like other shamrocks?

Answer: Hi Belinda. These colourful shamrocks will die back naturally for a dormant period. I have always grown Oxalis triangularis as a frost tender plant although I think is probably much tougher than this if it is grown in well drained soil. To be on the safe side I would suggest that you move your containers to a frost free position, and cover the border grown plants with a thick, dry mulch of barks chips to keep them snug over winter.

Wet soil will cause them to rot during dormancy. Whilst you have little control over this outdoors, you can help your containers plants by keeping the soil just moist during their dormancy. You can resume watering in spring when the new growth emerges.